Counting Rabbits

The teacher asked Johnnie, "Johnnie if I gave you two rabbits and then two more rabbits and then two more rabbits, how many would you have?"

Johnnie replied, "Seven rabbits, Teacher."

The teacher asked again, "Listen Johnnie, If I gave you two rabbits, plus two more rabbits, plus two more rabbits... How many rabbits would you have altogether?"

Johnnie smiled, "That's easy, Teacher, I would have seven."

"Ok Johnnie," the teacher said. "Let's try it a different way. If I gave you two bottles of root beer, plus two more bottle of root beer, plus two more bottle of root beer. How many bottle of root beer would you have?"

"Six bottle." Johnnie said.

"OK," said the teacher. "Now think of that with this question. "If I gave you two rabbits, then two more rabbits, then two more rabbits how many would you have?"

"Seven, Teacher." Johnnie said.

"Why seven?" the teacher asked, exasperated.

Johnnie replied, "Because I already have one rabbit at home!"